If you don't re-address each element, how do you map the value at index 1 to index 0? One way is to leave the indexes intact and keep an offset around, so you

If you don't re-address each element, how do you map the value at index 1 to index 0? One way is to leave the indexes intact and keep an offset around, so you may map the nth logical index to the nth physical one. (Add 1 on a shift, subtract 1 on an unshift.) But if you wanted this behaviour, there are more efficient ways: http://en.wikipedia.org/wiki/Circular_buffer http://en.wikipedia.org/wiki/Circular_buffer